Solitary pulmonary nodule of benign metastasizing leiomyoma associated with primary lung cancer: a case report

INTRODUCTION: Benign metastasizing leiomyoma in the lung is a very rare disease characterized by the growth of uterine leiomyoma tissue. In most cases there is a previous history of hysterectomy for uterine leiomyoma. CASE PRESENTATION: A 50-year-old Asian woman underwent a total abdominal hysterectomy for uterine leiomyoma at the age of 37 years old. She was referred to our hospital because of sudden anterior chest pain. A chest computed tomography scan revealed a ground-glass opacity in her left S10 lung segment and a solitary small nodule in her left bronchial segment, S4. We performed a left lower lobectomy and an upper lung partial resection in order to make a definitive diagnosis and to enable us to determine a further therapeutic strategy. The ground-glass opacity in her left S10 was a primary lung adenocarcinoma, while the small nodule in her left S4 was diagnosed as a benign metastasizing leiomyoma. No additional therapy was done and our patient was followed up with chest computed tomography. Up to date, repetitive evaluation by chest computed tomography has shown no sign of benign metastasizing leiomyoma or lung cancer recurrence. CONCLUSION: This is a very rare case of benign metastasizing leiomyoma of the lung associated with primary lung cancer. This comorbid association should be considered in the differential diagnosis when a solitary lung nodule is detected in a patient with a history of uterine leiomyoma.